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Effect of Lorentz local field correction on propagation of ultrashort laser pulse in one-dimensional para-nitroaniline (PNA) molecules 下载免费PDF全文
This paper investigates the effect of Lorentz local field correction (LFC) on the propagation of ultrashort laser pulses in a para-nitroaniline molecular medium under resonant and nonresonant conditions by solving numerically the full-wave Maxwell-Bloch equations beyond slowly-varying envelope approximation and rotating-wave approximation. The effect of the LFC is considerably obvious when pulses with large areas propagate in the dense molecular medium. In the case of resonance,the group velocity of the sub-pulses split from the incident pulse along propagation is severely decreased by the LFC,especially for the latest sub-pulse. However,in the case of nonresonance,the influence of the LFC on the temporal evolution of the pulse is less obvious and lacks homogeneity with an increase in incident pulse area,propagation distance and molecular density. 相似文献
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Ab Initio Studies of Radicals HBX(X=H,F, Cl,Br): Molecular Structure,Vibrational Frequencies and Potential Energy 下载免费PDF全文
We describe high-level ab initio calculations on the BH_2, HBF, HBCl and HBBr radicals. Molecular structure,vibrational frequencies and potential energy curves of the ground state and the first excited state, which are two Renner-Teller components for a~2Π state at linearity, are studied using the basis sets aug-cc-pVTZ and icMRCI+Q technique. On the basis of the potential energy curves, a reliable potential energy barrier to dissociation HB+X(X=F, Cl, Br) fragments and to linearity are given. The ab initio results will add some understanding on the spectrum and the photo-dissociation dynamics of the series of radicals. 相似文献
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研究了频率失谐时共振拉曼散射的动力学过程.当入射光子能量远离共振吸收能量时,时域内的失相使散射过程变快.这使得频率失谐如同照相机的快门功能,具有规律的散射持续时间,为普通的稳态测量提供了控制散射时间的有效工具.基于这个理论对两个多模式模型系统以及反式-1,3,5-己三烯和鸟嘌呤-胞嘧啶Watson-Crick碱基对分子的共振拉曼光谱进行了研究.除了这些特殊的物理效应,快散射机制可以简化光谱,同时使散射理论得到简化.当入射光子频率在共振区域时,拉曼光谱中会出现较强的多倍频成分;当入射光子频率与第一共振吸收频率之间的失谐量为振动能量时,在快散射过程中,这些多倍频成分逐渐消失.因此,利用入射光子与共振频域的失谐可以明显地简化拉曼光谱,从复杂光谱中去除多倍频和软模的影响,并且可以避免共振态的解离和荧光衰减引起的干扰. 相似文献
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以一维不对称π共轭分子体系(DBASVP分子)为介质,在双光子共振条件下,从双光子面积定理和严格数值求解Maxwell-Bloch方程两方面出发,分别研究超短脉冲激光在该有机分子介质中的传播过程,从而探讨双光子面积的演化规律,并分析双光子面积定理的适用性.提出了一种数值模拟分子介质光限幅特性的理论方法.分子的电子结构和电偶极矩是基于密度泛函理论利用从头计算方法得到的.研究结果表明,基于慢变幅和慢变相近似以及单模场条件下的双光子面积定理不能很好地描述超短脉冲的双光子面积在该分子介质中的演化规律.基于双光子吸收的分子光限幅特性与分子介质的厚度有关.
关键词:
双光子吸收
光限幅效应
双光子面积定理
超短脉冲激光 相似文献
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